Hill vs Siemian why is there a debate?

I think the only debate we'll be having is which QB we'll be throwing under the bus when he doesn't perform like we think he should. In my mind we have an equal amount of chance for success with either TH or TS. My only worry about starting TH is whether he is ready to step in and start after being out for this long nursing a concussion. If he starts, expect him to be a bit rusty. TS has been practicing as the QB2 while TH was hurt, he may be the more ready QB right now. I would hope that TS gets the start so that TH will have another week of practice before getting the start next week.